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US 3,944,295 AGranted
Towing valve arrangement for fail-safe brake system
AssigneeCaterpillar Tractor Co.
InventorsMichael K. Lloyd, Paul C. Rosenberger
Life of this patent
Estimating the term…
Abstract
A brake system having spring applied fluid pressure released brakes is provided with an auxiliary source of pressure for release of the brakes and a valve that is locked into an inoperative position effective to thereby render it tamper-proof.
Claims9
A vehicle brake control system having spring applied brake means and fluid pressure responsive release means;
- a brake control valve for controlling said brakes;
- a primary source of fluid pressure for controlling said brakes;
- an auxiliary source of fluid pressure for controlling said brakes upon failure of said primary source;
- an auxiliary control valve comprising a valve body, a valve spool reciprocably mounted in said valve body and movable between a communicating position and a noncommunicating position, for controlling communication of said auxiliary source with said control valve, both ends of said valve extending from said valve body;
- and,
- locking means including a bracket operative to engage both ends of said spool and adapted to be secured in a fixed position to block movement of said spool to said communicating position.
3 more elements
A fluid control system for operating a fluid responsive motor;
- a main control valve for controlling said motor;
- a primary source of fluid pressure for operating said motor;
- an auxiliary source of fluid pressure for operating said motor upon failure of said primary source;
- an auxiliary control valve comprising a valve body, a valve spool reciprocably mounted in said valve body and movable between a communicating position and a noncommuicating position for controlling communication of said auxiliary source with said control valve, said valve spool having both ends extending from said valve body;
- and,
- locking means including a bracket, said bracket being operative to engage both ends of said spool and adapted to be secured in a fixed position to block movement of said spool to said communicating positon.
3 more elements
A safety control valve for operating a fluid system comprising:
- a control valve having a communicating position and a noncommunicating position;
- a control valve comprising a valve body, a valve spool reciprocably mounted in said valve body and movable between a communicating position and a noncommunicating position, for controlling communication of fluid from a source, said valve spool extending from both ends of said valve body;
- and,
- locking means including a bracket, said bracket being operative to engage both ends of said spool and adapted to be secured in a fixed position to block movement of said spool from a selected one of said communicating and noncommunicating positions.
1 more element
Dependencies are inferred from the claim text.